Coaxial cable stripper

ABSTRACT

A coaxial cable stripper, consisting of:—a cutting unit ( 1 ) comprising cutting means ( 7 ) for a plurality of sheaths, said cutting unit ( 1 ) being designed to surround a cable ( 5 ) and cut its sheaths simultaneously by rotation of said cutting means ( 7 ) about the cable ( 5 ),—an intermediate unit ( 2 ) designed to surround said cable ( 5 ) and comprising means ( 6, 29 - 31 ) for adjusting the rotation of said cutting means ( 7 ),—a fixing unit ( 3 ) comprising fixing means ( 8 ) for said cable ( 5 ), the three units ( 1 - 3 ) being adjacent to one another and aligned along a common axis defined by said cable ( 5 ).

[0001] The present invention relates to a coaxial cable stripper. Bycoaxial cables is meant electric cables consisting of a plurality ofconcentric conductors mutually separated by sheaths. According to thisdefinition, therefore, a triaxial cable, for example, must be deemed tobelong to the family of coaxial cables and hence to be included amongstthose cables which can be used with the stripper according to theinvention.

[0002] The prior art contains different types of strippers for coaxialcables. In this regard may be cited those which are described inEP-A-397319, DE-A-11365, U.S. Pat. No. 4,987,801, U.S. Pat. No.4,059,893, EP-A-140397, EP-A-81865 and EP-A-432957.

[0003] The strippers of the prior art suffer, however, from a certainnumber of drawbacks: the precision of the cut often leaves something tobe desired. The complexity of the devices makes them fragile, thisfragility has its origin in the fact that the cutting means are actuatedor adjusted by springs, inevitably imprecise elements, which are placedin their vicinity. Moreover, for the majority of the devices, theirlarge relative size does not allow them to be easily transported, forexample in the pocket or bag of the user.

[0004] The present invention offers, in particular, the advantages ofremedying the aforesaid problems. It relates to a coaxial cablestripper, consisting of:

[0005] a cutting unit comprising cutting means for a plurality ofsheaths, said cutting unit being designed to surround a cable and cutits sheaths simultaneously by rotation of said cutting means about thecable,

[0006] an intermediate unit designed to surround said cable andcomprising means for adjusting the rotation of said cutting means,

[0007] a fixing unit comprising fixing means for said cable,

[0008] the three units being adjacent to one another and aligned along acommon axis defined by said cable, said stripper being characterized inthat:

[0009] the cutting unit consists of a cylindrical housing which is openon that side of its base which is in contact with the intermediate unit,the inside of the housing consisting of at least:

[0010] a) two rotary cutting disks comprising an opening in their centerfor passage of the cable, the face of each rotary disk which is oppositethe intermediate unit consisting of a swivel blade designed to cut thesheaths of the cable, the other face consisting of means for fixedlyconnecting with the adjacent disk and means for pivoting the blade,

[0011] b) a rotary guide disk comprising guide means for said blades,said guide disk being fixedly connected to the cutting disk which isadjacent thereto by means of said connecting means,

[0012] the back of the housing additionally consisting of driving meansfor the rotary cutting disk which is adjacent thereto;

[0013] the intermediate unit is fixedly connected to the fixing unit.

[0014] The absence of a spring at the level of the cutting means lends acertain robustness to the device, resulting in marginally greatercutting precision.

[0015] The device according to the invention can additionally havesmaller dimensions, for example between 10 and 20 cm in length and adiameter between 5 and 10 cm.

[0016] According to one embodiment, the cutting disks comprise meanswhich allow adjustment of the cutting depth.

[0017] In a variant of the invention, the guide disk consists of acylinder which surrounds the cable and which comprises a set of slotsserving as guides for the blades as they are pivoted.

[0018] In another variant, the guide disk itself comprises cuttingmeans.

[0019] Preferably, the adjusting means of the intermediate unit consistof two disks, the first disk remaining fixedly connected to the assemblyformed by the intermediate unit and the fixing unit, the second diskbeing designed to rotate about the cable whilst exerting a friction uponthe first disk.

[0020] The different embodiments of the invention which are set outabove can equally be used conjointly in one and the same device.

[0021] Of course, the stripper according to the invention may containmore than two cutting disks.

[0022] According to a preferred embodiment, three cutting disks are usedand the guide disk is also provided with cutting means. Thisconfiguration is intended for the stripping of triaxial cablescomprising four sheaths to be cut.

[0023] A detailed illustrative embodiment of the invention will bedescribed below with reference to the following figures:

[0024]FIG. 1 represents a stripper according to the invention.

[0025]FIG. 2 shows essentially a disassembled cutting unit.

[0026]FIG. 3 represents a cutting disk, in front view, in a firstconfiguration.

[0027]FIG. 4 shows the same disk as FIG. 3, but in anotherconfiguration.

[0028]FIG. 5 shows diagrammatically the disk of FIGS. 3 and 4 in rearview.

[0029]FIG. 6 illustrates a longitudinal section of the stripper of FIG.1.

[0030] The stripper represented in FIGS. 1 to 6 is constituted by acutting unit 1, an intermediate unit 2 and a fixing unit 3. It isdesigned to strip a triaxial cable. The inside of the stripper (seeFIGS. 2 and 6) comprises a longitudinal channel intended to receive inremovable fashion a coaxial cable 5. The cutting unit 1 consists of acylindrically shaped housing 9, the external surface of which isprovided with longitudinal serrations serving to facilitate the graspingand rotation of the cutting unit 1 by a user. The base 10 of the housing9, located on the side of the intermediate unit 2, is open. The insideof the housing contains a disk 23 fixed to the back 22 of the housing 9by screws 34, three cutting disks 11-13 and a guide disk 19.

[0031] The three cutting disks 11-13 are of identical structure, apartfrom their thickness, which can vary. In the example which isillustrated here, each disk has a different thickness. As will be seenlater, the choice of thickness of the disks 11-13 determines thedistance between two cutting zones. With particular reference to FIGS. 3and 4, it will be noted that the face 15 of the disks 11-13 which isdirected toward the back 22 of the housing 9 comprises a swivel blade 7provided with a longitudinal slot 37. The position of its pivot 28 issuch that the blade 7 can cut the sheaths of a cable 5 which passesthrough the opening 14 in the disk 11-13.

[0032] On the same face 15, the disk 11-13 additionally comprises twocircular-arc-shaped slots 26, 27, the first slot 26 being disposedtoward the periphery of the disk 11-13, the second 27 being locatedbetween the pivot 28 of the blade 7 and the central opening 14 in thedisk. The disk also comprises two circular-arc shaped recesses 38, 39,the presence of which allows the total structure forming the stripper tobe made lighter.

[0033] As can be seen in FIG. 5, the second face 16 of each disk 11-13comprises two pivots 17, 18 disposed perpendicularly to the face 16 ofthe disk 11-13. The first pivot 18 is placed toward the periphery of thedisk 11-13 and is designed to shift position inside the first slot 26 ofthe adjacent disk. The second pivot 17 is placed close to the centralopening 14 and is designed to pass through the longitudinal slot 37 ofthe blade 7 of the adjacent disk and to shift position inside the secondslot 27 of this same disk. The maximum displacement of the pivots 17, 18in their respective slots 26, 27 is adjustable by virtue of a systemconsisting of a screw 25, the end of which can be inserted into thefirst slot 26.

[0034] The disk 23 fixed onto the back 22 of the housing 9, on its facedirected toward the intermediate unit 2, also comprises pivots 17, 18,which are identical in their technical and functional characteristics tothose of the other cutting disks (see FIG. 5).

[0035] The guide disk 19, apart from the zone adjoining its centralopening, has a configuration similar to that of the first faces 15 ofthe cutting disks 11-13. The central part of the guide disk 19 consistsof an extension in the shape of a cylinder 20, the external diameter ofwhich is such that it can pass through the openings in the other disks11-13, 23. The end of the cylinder 20 is situated toward the back of thehousing 9 and extends slightly beyond this to terminate outside thehousing 9. At the level of the fixed disk 23, the cylinder 20 comprisesa circular groove 36 intended to receive in sliding fashion a screw 35housed in the fixed disk 23. The presence of the circular groove 36 andof the sliding screw 35 ensures the retention of the set of disks 11-13,19, and their movable contact with the fixed disk 23 and the housing 9to which it is fixed. The cylinder 20 additionally comprises a series ofslots 21 (see FIG. 2), which act as a guide for the blades 7.

[0036] The intermediate unit 2 consists of a cylindrical sleeve 29fixedly connected to the cylinder 20 of the guide disk 19, a rotary disk30 fixedly connected to the sleeve 29 by screws 32, and a fixed disk 31exerting a friction upon the rotary disk 30 via springs 6, whichsurround screws 24 disposed perpendicularly to the two disks 30, 31.

[0037] The fixing unit 3 is fixedly connected to the intermediate unit 2by means of screws 33.

[0038] It consists of a system of clamps 8, which prevent the rotationand translation of the cable 5 when this is placed in the stripper, thefixing of the cable 5 being realized by screwing the outer casing of thefixing unit 3 in the direction of the intermediate unit 2.

[0039] The stripper which has previously been described operates asfollows:

[0040] Prior to the introduction of the cable 5, the cutting depth ofeach blade 7 is defined by adjusting the depth of the adjusting screw 25of the first slot 26 of the cutting disks 11-13. The friction forcebetween the rotary disk 30 and the fixed disk 31 of the intermediateunit is adjusted by action upon the screws 24 present inside the springs6.

[0041] The different elements are then assembled. With one of his hands,the user effects a rotation of the housing 9 of the cutting unit 1 inthe clockwise direction, the other hand preferably grasping the fixingunit 3. This gesture produces a displacement in the same direction ofthe pivots 17 passing through the blades 7. The latter are then distantfrom the central opening 14 in the cutting disks 11-13, 19. The cablecan thus be introduced into the stripper, preferably on the side of thefixing unit 3. The cable 5 is next fixed in the fixing unit 3. In thisconfiguration, the stripper is ready for the cutting of the sheaths. Theuser effects a rotation of the housing 9 of the cutting unit 1 in thecounter-clockwise direction. The blades converge and penetrate into thedifferent sheaths at previously defined depths.

[0042] It will here be noted that the speed of rotation of the blades 7about the cables, as well as the quality of the cut, are determined bythe adjustment of the screws 24 which, through the use of springs 6,alter the friction between the rotary disk 30 and the fixed disk 31 ofthe intermediate unit 2. The speed of rotation of the blades will be allthe higher, and the cutting quality diminished, if the friction betweenthe two disks 30, 31 is weak.

[0043] Although it is theoretically possible to effect a single rotationof the housing 9 to cut the sheaths, the user must carry out a fewrotations in order to ensure that complete cuts have been made.

[0044] At the end of these rotations, the user firstly frees the cable 5at the level of the fixing unit 3, he then applies a traction to thecable, preferably from the side of the stripper where the fixing unit 3is found. The cable 5 is thus able to depart the stripper and thecut-off sheaths remain temporarily inside the stripper before beingremoved, in turn, by shaking of the stripper and rotation of the housing9 in the clockwise direction so as to release the blades from thecentral opening 14 in the cutting disks 11-13, 19.

[0045] Self-evidently, the invention is not limited to the exampledescribed above. The number of cutting disks is not, of course, limitedto four.

[0046] As a non-illustrated option for determining the distance betweenthe cutting zones, the presence of circular rings between the cuttingdisks can also be envisaged, the thickness and/or number of these ringsallowing an adjustment of the distance between the cutting zones.

[0047] It is finally worth pointing out that the blades used within theframework of the present invention can be standard, which makes thesubject of the invention relatively economical.

1. A coaxial cable stripper, consisting of: a cutting unit (1)comprising cutting means (7) for a plurality of sheaths, said cuttingunit (1) being designed to surround a cable (5) and cut its sheathssimultaneously by rotation of said cutting means (7) about the cable(5), an intermediate unit (2) designed to surround said cable (5) andcomprising means (6, 24, 29-32) of adjusting the rotation of saidcutting means (7), a fixing unit (3) comprising fixing means (8) forsaid cable (5), the three units (1-3) being adjacent to one another andaligned along a common axis defined by said cable said stripper beingcharacterized in that: the cutting unit (1) consists of a cylindricalhousing (9) which is open on that side of its base (10) which is incontact with the intermediate unit (2), the inside of the housing (9)consisting of at least: a) two rotary cutting disks (11-13) comprisingan opening (14) in their center for passage of the cable (5), the face(15) of each rotary disk (11-13) which is opposite the intermediate unit(2) consisting of a swivel blade (7) designed to cut the sheaths of thecable (5), the other face (16) consisting of means (18) for fixedlyconnecting with the adjacent disk (11-13, 19) and means (17) forpivoting the blade (7), b) a rotary guide disk (19) comprising guidemeans (20, 21) for said blades (7), said guide disk (19) being fixedlyconnected to the cutting disk (11) which is adjacent thereto by means ofsaid connecting means (18), the back of the housing (22) additionallyconsisting of driving means (18) for the rotary cutting disk (13) whichis adjacent thereto; the intermediate unit (2) being fixedly connectedto the fixing unit (3).
 2. The stripper as claimed in the precedingclaim, characterized in that that side (15) of a rotary cutting disk(11-13) which consists of the swivel blade (7) also consists of means(25) for adjusting the positioning of the connecting means (18) locatedon the face (16) of the adjacent disk, this in order to allow anadjustment of the cutting depth of the blades (7).
 3. The stripper asclaimed in claim 1 or 2, characterized in that the rotary guide disk(19) comprises a cylinder (20) intended to surround the cable (21), saidcylinder (20) comprising a series of slots (21) which are disposedperpendicularly to the direction defined by the cable (5) and aredesigned to guide the blades (7) as they are pivoted.
 4. The stripper asclaimed in any one of the preceding claims, characterized in that saidconnecting means (18) and said means (7) for pivoting the blade arepivots disposed perpendicularly to the faces (15, 16) of the disks(11-13), the connecting pivot (18) entering into contact with a firstcircular-arc-shaped slot (26) made on the face (15) of the oppositedisk, the pivot (17) acting on the blade (7) entering into contact witha second circular-arc-shaped slot (27) made on a part of the blade (7).5. The stripper as claimed in any one of the preceding claims,characterized in that the guide disk (19) also comprises cutting means(7).
 6. The stripper as claimed in any one of the preceding claims,characterized in that the adjusting means (6, 29-31) of the intermediateunit (2) consist of two disks (30, 31), the first disk (31) remainingfixedly connected to the assembly formed by the intermediate unit (2)and the fixing unit (3), the second disk (30) being designed to rotateabout the cable (5) whilst exerting friction upon the first disk (31).7. Method of use of a stripper according to any one of the claims,characterized in that a rotation in one direction of the cutting unit(1) results in the blade (7) being moved toward the sheath to be cut andin that an oppositely directed rotation results in the blade (7) beingmoved further away from the sheath.